a darkout is a person who misteriously decides not to participtate in an event. They can only manage to provide justification in the form of such responses as "i don't feel like it" or "i can't be bothered". It has been found that darkouts are often a result of the subject harbouring agendas that they fear would induce ridicule.

For fucks sake, don't darkout on us again

tom's darked out on us again! he's ditched us to go with his girlfriend to see the corrs. what a fucking girl bummer!